It is evident that better prognostic markers for malignant melanoma are needed to improve conventional pathological staging of disease, disease characteristics and in designing efficient disease management therapeutical approaches. We have developed an extensive melanoma computerized data bank of melanoma patients seen at JWCI the last 21 years. Along with this we have archival paraffin and cryopreserved melanoma biopsy tissues of primaries and paired metastases. We will evaluate a biochemical (ganglioside) as well as a genetic markers as potential prognostic markers in a univariate and multivariate analysis with other prognostic markers using these patients resources. The detection of metastatic tumor cells in tissue and body fluids is also an important marker of tumor progression. Cutaneous melanoma predominantly metastasizes to tumor-draining lymph nodes (TDLN). The detection of occult melanoma micrometastases in TDLN is important in disease staging, prognosis, surgical and adjuvant therapy. In our Institute we developed a surgical mapping procedure to identify the "sentinel" lymph node of a TDLN group most likely to contain micrometastases. The objective of the study is to develop a more sensitive assay to improve the detection of these occult melanoma cells. A specific polymerase chain reaction assay for specific melanoma markers will be used to detect occult melanoma cells in TDLN, which may be applicable to body fluids. The hypothesis is that by using the surgical mapping procedure with the sensitive occult tumor cell detection assay, we will improve disease staging and management decisions on elective lymphadenectomy (ELND). In this way, patients with occult metastases will undergo ELNDs that are indeed therapeutic.